Detecting and monitoring early cognitive impairment in Alzheimer's disease (AD) is a significant need in the field of AD therapeutics. Successful AD clinical trial designs have to overcome challenges related to the subtle nature of early cognitive changes. Continuous unobtrusive assessments using Information and Communication Technology (ICT) devices to capture markers of intra-individual change over time to assess cognitive and functional disability therefore offers significant benefits. We review the literature and provide an overview on randomized clinical trials in AD that use intelligent systems to monitor functional decline, as well as strengths, weaknesses, and future directions for the use of ICTs in a new generation of AD clinical trials.